Commit Graph

4 Commits

Author SHA1 Message Date
Szabolcs Nagy c156098271 New expf, exp2f, logf, log2f and powf implementations
Based on code from https://github.com/ARM-software/optimized-routines/

This patch adds a highly optimized generic implementation of expf,
exp2f, logf, log2f and powf.  The new functions are not only
faster (6x for powf!), but are also smaller and more accurate.
In order to achieve this, the algorithm uses double precision
arithmetic for accuracy, avoids divisions and uses small table
lookups to minimize the polynomials.  Special cases are handled
inline to avoid the unnecessary overhead of wrapper functions and
set errno to POSIX requirements.

The new functions are added under newlib/libm/common, but the old
implementations are kept (in newlib/libm/math) for non-IEEE or
pre-C99 systems.  Targets can enable the new math code by defining
__OBSOLETE_MATH_DEFAULT to 0 in newlib/libc/include/machine/ieeefp.h,
users can override the default by defining __OBSOLETE_MATH.
Currently the new code is enabled for AArch64 and AArch32 with VFP.
Targets with a single precision FPU may still prefer the old
implementation.

libm.a size changes:
arm: -1692
arm/thumb/v7-a/nofp: -878
arm/thumb/v7-a+fp/hard: -864
arm/thumb/v7-a+fp/softfp: -908
aarch64: -1476
2017-10-13 10:58:00 +02:00
Jeff Johnston 664f00763b 2009-07-09 Craig Howland <howland@LGSInnovations.com>
* libm/math/ef_scalb.c:  Replace isnanf() (pre-C99 function call) with
        isnan() (C99 macro).
        * libm/math/wf_log.c:  Ditto.
        * libm/math/wf_j0.c:  Ditto.
        * libm/math/wf_sqrt.c:  Ditto.
        * libm/math/wf_pow.c:  Ditto.
        * libm/math/wf_fmod.c:  Ditto.
        * libm/math/wf_remainder.c:  Ditto.
        * libm/math/wf_scalb.c:  Ditto.
        * libm/math/wf_atanh.c:  Ditto.
        * libm/math/wf_cosh.c:  Ditto.
        * libm/math/wf_acos.c:  Ditto.
        * libm/math/wf_acosh.c:  Ditto.
        * libm/math/wf_jn.c:  Ditto.
        * libm/math/wf_log10.c:  Ditto.
        * libm/math/wf_asin.c:  Ditto.
        * libm/math/wf_j1.c:  Ditto.
        * libm/common/sf_isnan.c:  Add #include <ieeefp.h>, fix comment.
        * libm/common/sf_isinf.c:  Add #include <ieeefp.h>, adjust comment to
        match that from s_isinf.c.
        * libc/include/machine/ieeefp.h:  Simplify isinf and isnan macros to
        remove un-necessary extension use (in a similar manner to as was
        recently done in math.h).
        * libc/include/math.h:  Remove isnanf and isinff prototypes (are in
        ieeefp.h).
        * libm/machine/spu/sf_isinf.c:  Fix comment (remove <math.h>).
2009-07-09 17:04:56 +00:00
Jeff Johnston 2babeb3d94 2007-05-01 Cary R. <cygcary <at> yahoo.com>
* libm/math/e_pow.c: Fix to be consistent with glibc with regards
        to treatment of NaN and +-inf arguments.
        * libm/math/ef_pow.c: Ditto.
        * libm/math/w_pow.c: Ditto.
        * libm/math/wf_pow.c: Ditto.
        * libm/math/w_acos.c: Fix domain errors to return NaN.
        * libm/math/w_asin.c: Ditto.
        * libm/math/wf_acos.c: Ditto.
        * libm/math/wf_asin.c: Ditto.
        * libm/math/w_log.c: Fix to return NaN for negative number inputs.
        * libm/math/wf_log.c: Ditto.
        * libm/math/wf_log10.c: Ditto.
        * libm/math/w_log10.c: Ditto.
2007-05-01 18:42:15 +00:00
Christopher Faylor 8a0efa53e4 import newlib-2000-02-17 snapshot 2000-02-17 19:39:52 +00:00